How to dissolve geodes matrix

Jewelry Discussion
#1

Does anyone know what acid or other material that will dissolve the
stone around a geode without dissolving the quartz crystals.

Take care,
Tina
CreatedWithFire Studios

#2

Unfortunately, the material surrounding the quartz crystals in the
center of the geode is frequently cryptocrystalline quartz. so
anything that will dissolve the surrounding material will dissolve
the interior also.

john

#3 
Does anyone know what acid or other material that will dissolve the
stone around a geode without dissolving the quartz crystals.

Grinding wheels, judiciously applied.

Noel

#4 
Does anyone know what acid or other material that will dissolve
the stone around a geode without dissolving the quartz crystals.

Nothing on Earth that I am aware of…

#5

Most acids will not dissolve quartz. The exceptions are those used to
etch glass for example Hydrofluoric Acid which is a very nasty stuff
not to be used by the general public. If the material around the
geode contains calcium carbonate in some amount you can dissolve it
and the rest will become a sand of sediment that can be washed away.
For that Acetic acid is great. A test would be to apply the acid and
look for bubbles. If there are bubbles with vinegar then you can
expect to break it down. Even with this there may be “rind” that will
not come off. A good example are the flints in Southern England which
are essentially like a geode. They come from the chalk which although
not a carbonate is easily broken down. Labs which test oil well
cores, break them up to get out foraminifera to assist in aging the
rock will use ultrasonics to get them out.

#6

Thanks John, I know hubby is planning on trying several of the acids
we have around the house…this should be fun huh… and yes he will
be using ppe and be outside but I will send him your and
let you know how it works !

Take care,
Tina